Expanding head



Dec. 24, 1946. f A. 1.. FORBES, JR: 2,413,103

EXPANDING HEAD Filed Oct. 26, 1944 3 Sheets-Sheet 1 Dec. 24, 1946.FORBES, JR 2,413,103.

EXPANDING HEAD Filed Oct. 26, 1944 3 SheetsSheet 2 A. L. FORBES, JR

EXPANDING HEAD Filed Oct. 26, 1344 3 Sheets-Sheet 6 1 Patented Dec. 24,1946 EXPANDING HEAD Arthur L. Forbes, Jr., Houston, Tex., assignor toPressure Weld Company, Houston, Tex., a corporation of DelawareApplication October 26, 1944, Serial No. 560,473

2 Claims. 1

This invention relates to an expanding head, particularly adapted foruse in the process of welding pipes together.

The head has been particularly designed for use in the construction ofpipe lines whose sections are welded together.

Another object of the invention is to provide an expanding head of thetype described which is adapted to be located within the adjacent endsof the pipes to be welded together and which includes means forexpanding the head against said adjacent ends so that the ends will bebrought to perfectly round shape, if out of round, in order that theends to be welded together will perfectly register.

A further object of the invention resides in novel means for expandingthe head.

It is a further object of the invention to provide, in a head of thecharacter described, retractable stops provided to accurately locate thehead with respect to the joint between the pipe sections with means forretracting the stops upon initial expansion of the head.

With the above and other objects in view the invention has particularrelation to certain novel features of construction, operation andarrangement of parts, an example of which is given in this specificationand illustrated in the accompanying drawings, wherein- Figure 1 shows alongitudinal, sectional view of the head.

Figure 2 shows an enlarged, fragmentary, sectional view of the pressureapplying means for retracting the stops and expanding the head.

Figure 3 shows an end view of the head.

Figure 4 shows a sectional view taken on the line 44 of Figure 1; and

Figure 5 shows a plan view of the head located in the pipe line andshown in active, or expanded, position.

Referring now more particularly to the drawings, wherein like numeralsof reference designate the same parts in each of the figures, thenumerals I and 2 designate inner and outer plates which are arrangedconcentric. There is a tubular nipple 3, concentric with and extendedthrough both plates. It is welded to the plate 2 and extends through andbeyond the plate I. Its extended end is outwardly threaded. A tubularbushing 4 is extended through the nipple and is screwed onto thethreaded end of the nipple and is formed with a head which abuts theouter side of the plate I. Around the nipple and between the platesthere is an annular spacer 5. The parts hereinabove referred to may bedesignated as the frame of the head and, of course, may be varied inspecific construction.

Around this frame are the shoes 6, four of said shoes being shown. Theyare of arcuate shape, 5 their outer surfaces being curved to conform tothe desired inside contour of the pipe-that is, the outer surfaces ofthe shoes, when the head is expanded, are of a cylindrical contour. Eachshoe has a plate like web '1 which extends radially inwardly between theplates of the frame as more accurately shown in Figure l.

The frame plates have the marginal registering slots 8 and 9 as shown inFigures 1 and 4. The slots 8 are somewhat wider, and extend somewhatfurther radially inwardly, than the slots 9. The webs I also have themarginal slots III which register with the slots 9.

Fastened to the webs on opposite sides of the slots I0 thereof andextending outwardly through the slots 8 are the pairs of lugs II, II,the lugs of the respective pairs being spaced apart. Toggle links I2have their outer ends pivoted between the respective pairs of lugs IIand have their inner ends pivotally connected to a. hub I3. This hub isfixed on a plunger rod I4 whose inner end slides through the bushing 4and a strong coil spring I5 surrounds said rod and is interposed betweenthe frame and the hub I3 and normally holds the hub outwardly thusholding 3 the shoes 6 inwardly or in retracted position. The hub I3 andspring I5 are surrounded by a housing I I5 which may be .bolted to theframe and whose outer end is formed with a central bear ing throughwhich the plunger rod I4 works. The housing I6 has suitable side slotsI! through which the toggle links I2 may work.

- Fastened to the outer end of the housing I6 there is a cylinder I8within which there is a plunger I9 connected to the outer end of theplunger rod I4. Connected into the outer end of the cylinder l8 there isa suitable pressure line 20 through which a pressure fluid such as oilmay be admitted into the cylinder I8.

Upon application of pressure to the plunger I9 it is obvious that itwill be forced inwardly overcoming the pressure of the spring I5 andoperating, through the toggle links I2, to expand the shoes of thepressure head.

Bolted, or otherwise secured, to the frame plate I, there is a, hood 2|which surrounds and encloses the'corresponding end of the bushing l andthe plunger rod I 4.

Fastened to the innerend of the hood 2I there is a cylinder 22reciprocable in which there is a plunger 23 and fastened to this plungerand surrounding the outer end of the cylinder 22 there is a cap 24having an outwardly extended inner end flange 25.

Connected into the inner end of the cylinder 22 there is a valve housing26 having an inlet passageway 21 which is controlled by the inlet valve28 normally held closed by a pressure spring 29. A line 30 leads fromthe outer end of the cylinder I8 and is connected into the inletpassageway 21, as shown in Figure 2. The inlet passageway 21 also formsa relief passageway which is controlled by-the relief valve 30a. Thepurpose and operation of these valves will be hereinafter morespecifically explained.

On opposite sides of the slots 9 and secured to the frame plate I arethe pairs of arms 3|, 31 more accurately shown in Figures 1 and 3. Thearms of each pair are spaced apart and pivotally mounted between themare the stop members 32, shown more accurately in Figure 1. These stopmembers are curved outwardly through the slots 9 and I and their outerends projected through corresponding openings 33 in the shoes 6, and forthe stops 34 whose forward sides are beveled, as shown in Figure 1.Formed integrally with the pivoted ends of the stop members 32 are thearms 35 which extend radially inwardly and whose inner ends engagebehind the flange 25 as shown in Figure 1. These arms are connected tothe hood 2I by means of the yieldable members 36 and the flange 25 isconnected to said hood by the yieldable members 31. These yieldablemembers 36, 31 are preferably in the form of coil springs.

Normally the spring I will hold the shoes 6 retracted, or in their innerposition, and the springs 36 will hold the stops 34 outwardly or inactive position. The head may be inserted into the end of the pipe line38, or other pipe to which a section is to be welded. The stops 34 willengage the end of the pipe line so as to regulate the distance ofinsertion. As is indicated in Figure 1 the shoes should be insertedabout one-half of their length into the pipe line. The section 39 to bewelded on may then be brought into alignment with the section 38 and itsend, adjacent the pipe line, or section, 38 moved over the shoes 6 intothe position indicated in dotted lines in Figure 1. Pressure may then beapplied through the line into the cylinder I8 and this pressure willpass also through the branch line b. The spring 29'may be made of anydesired strength, usually it is of a strength to require about fiftypounds pressure to open the valve 28 and admit pressure into thecylinder 22. This initial pressure will operate through the toggle linksI2 to cause the shoes to contact the opposing ends of the respectivepipes 38 and 39 and will force the plunger 23 and cap 24 outwardly thusacting through the arms to retract the stops 34. The section 39 may thenbe forced into direct contact with the end of the pipe line 38 by a pipewelding machine, or other appliance, adapted for the purpose and as thepressure in the cylinder I8 is further built up the shoes will befurther expanded and will bring the abutting ends of the pipes intoperfectly round shape, if out of round. The abutting ends may then bewelded together by the application of heat from the welding machinereferred to. When the weld is completed the ends of the pipe weldedtogether will be slightly up set inwardly and the head is provided 4with a circumferential groove 40 to provide space for the up setmaterial.

The pressure fluid may be supplied from any suitable source. When thepressure is relieved the spring I5 will force the plunger I9 outwardlyor in the reverse direction thus acting through the toggle links I2 towithdraw the shoes 6 inwardly and thus contract the head and the pull ofthe springs 31 will move the plunger 23 inwardly of its cylinder 22 thusforcing the pressure fluid back through the duct 21, past the reliefvalve 30a and through the branch line 30b and back through the line 30.

The head may then be withdrawn through the added section 39 until it isin the same relation to said added section, as is shown in Figure 1 andanother section added as before. The pressure line 20 may be used forwithdrawing the head and this line may be either a pipe or a hose ofsufficient strength for the purpose.

The head is provided with a carriage to facilitate its withdrawalthrough the added section 39. This carriage includes the rear wheels 4Imounted between the arms 3I as well as the front wheels 42 which aremounted between the forwardly extended arms 43 which are anchored to thefront plate 2 of the frame.

What I claim is:

, 1. An expanding head for registering the adjacent ends of alignedpipes to be welded together and for reshaping said ends, if distorted,comprising, a frame composed of concentric plates, means for fixing saidplates in spaced relation, a series of expanders mounted to moveradially on the frame and having curved outer faces arranged to movesimultaneously into contact with the inside of the pipe ends, uponoutward movement of the expanders, said faces when expanded defining anapproximately cylindrical contour, webs fixed to the expanders andextending radially inwardly between the plates, means responsive to thepressure of an operating fluid for moving the expanders outwardly tomove said faces into contact with the inside of the adjacent pipe endsand means for moving the expanders inwardly to released position uponrelief of said pressure.

2. An expanding head for registering the adjacent ends of aligned pipesto be welded together and for reshaping said ends, if distorted,comprising, a frame composed of approximately concentric members, meansfor fixing said members in spaced relation, a series of expandersmounted to move radially on the frame and having outer faces arranged tomove simultaneously into contact with the inside of the pipe ends uponoutward movement of the expanders, said faces when expanded defining anapproximately cylindrical contour, webs fixed to the expanders andextending radially inwardly between said members, radially movableretractable stops on the head which extend out beyond the head when theexpanders are in their inner position, means responsive to the pressureof an operating fluid for moving the expanders outwardly to move saidfaces into contact with the inside of the adjacent pipe ends, means forautomatically retracting said stops upon such movement and means formoving the expanders inwardly to released position upon relief of thepressure.

ARTHUR L. FORBES, JR.

